Well , maybe Tieke has a mistake labeling him "Oberst" or this Hauser does not fit as the was not even OTL before June 1944 ...
See above for possible solution:
On the other hand Martin Hornig, who took part in the battles as a member of Hauser's SPW regiment, referres to him in his memoirs (Geraubte Jugend) as Major Baron Hauser.
Tell me about it .Seems to be a quite tricky one !